Kent Larson
Dow Corning Electronics

Famous golfers are not the only ones who can wear a prized green coat. How about your automotive electronics? Are they wearing green?

Many of today's automotive circuit boards are benefited from the use of conformal coatings that allow them to reliably operate in rather harsh underhood environments. Conformal coatings have proven track records of protecting boards from dust and debris, liquids, and from contact with a wide gambit of harsh conditions thrown against them. Protective coatings work by forming a barrier to conductive contaminants that closely conforms over surfaces, components, wire bonds and solder joints. Additionally they electrically insulate and isolate conductors which may be in close proximity. Several studies have shown that silicones have been one of the best conformal coatings at slowing the formation and growth of these tin-whisker species. Additionally they may also deflect the growth direction which can prolong the expected life expectancy of the electronic assembly.

It is easy to concentrate on the price per kg when considering various types of coatings, but it is only part of the total cost of ownership. Likewise, materials which require a cure oven not only add capital costs when setting up a production line, but also incur energy costs to run. Other costs can include the cost of quality such as measured by first time reject and rework rates. Besides cost of ownership, performance criteria certainly must be met in automotive electronics.